The human brain and spinal cord are covered with meningeal membranes whose integrity is critical to the operation of the central nervous system. When the integrity of a person's meningeal membranes is intentionally or accidentally compromised, serious consequences may ensue, unless the membranes can be repaired. The meningeal membrane comprises three overlapping layers of tissue, which are in order from outside to inside, the dura mater (or dura), the arachnoid and the pia mater. Repairing damaged meningeal membranes has largely focused on implantable and/or resorbable constructs (known as dural substitutes) which are grafted to the damaged dura mater and are designed to replace and/or regenerate the damaged tissue.
Conventional dural substitutes are categorized as either onlay (e.g., sutureless) grafts or as suturable grafts. The onlay grafts overlap and contact the dura mater when covering an area of damaged dura mater. With such contact, the onlay grafts substantially conform to a geometry or general curvature of the meningeal membrane and/or brain. The weight of the onlay graft itself holds the graft in place to maintain the positioning of the graft relative to the tissue. Suturable dural grafts cover an area of damaged dura mater and attach to the meningeal membranes using sutures to maintain the graft in place.